The present invention relates generally to a golf club, and more particularly to a head of the golf club.
The conventional golf club heads are generally made of stainless steel, such as SUS 630 or SUS 431 (The U.S. AISI Standard 630 type and 431 type). The process is carried out by a precision dewaxing method. The density of such material is greater, while the strength of such material is lower. As a result, the conventional golf club heads have a certain wall thickness to meet the strength requirements that the golf club head should not be too heavy, and that the volume of the golf club head should not be too large. As a result, the scope of the sweet spot of the ball-hitting face of the golf club head is substantially reduced, thereby resulting in an increase in the rate of the ball-hitting failure.
The golf club head of titanium alloy has a density smaller than that of the stainless steel head, and a strength equal to that of the stainless steel head. However, the titanium golf club head is relatively expensive and must be made by a special vacuum melting pouring method at a high cost.
The primary objective of the present invention is to provide a golf club head free of the deficiencies of the conventional golf club head described above.
The golf club head of the present invention comprises a face which is made of a steel alloy containing maximum amounts of 0.03% carbon by weight, 0.2% of silicon by weight, 0.2% of manganese by weight, 0.2% of phosphor by weight, 0.02% of sulfur by weight, 10.5-11.0% of chromium by weight, 1.8-2.2% of molybdenum by weight, 9.5-10.5% of nickel by weight, 0.9-1.2% of titanium by weight, 0.5% of aluminum by weight, 0.1% of copper by weight, 0.3% of niobium by weight, 0.3% of boron by weight, 0.01% of nitrogen by weight, 0.1% of vanadium by weight, and 0.1% of tungsten by weight, with the rest being iron. The steel alloy is made by the metallurgical method requiring two vacuum melting processes. The steel alloy is of a metal quality of martensite.